TY - JOUR
T1 - UV-A induced delayed development in the larvae of coral Seriatopora caliendrum
AU - Zhou, Jie
AU - Fan, Tung Yung
AU - Beardall, John
AU - Gao, Kunshan
PY - 2017/2/1
Y1 - 2017/2/1
N2 - Coral reefs are vulnerable to ultraviolet radiation (UVR, 280–400 nm). Not only do the fluxes of UVR fluctuate daily, they are also increasing due to global ocean and atmospheric changes. The deleterious effects of UVR on scleractinian corals have been intensively studied, but much less is known about the response of corals in the early pre-settlement phase. In this study, we tested how UVR exposure affects survival and development of Seriatopora caliendrum larvae and examined the photophysiological changes induced in the symbiotic dinoflagellate Symbiodinium. Results showed that the contents of chl c and carotenoids normalized to the number of algae cells in the larvae decreased significantly when larvae were exposed to UVR compared to those protected from UVR, while the cell density of Symbiodinium was higher in UVR-exposed larvae. The effective photochemical efficiency of the symbiotic algae increased when cultured under PAR plus UV-A (here taken as 320–395 nm). We further present the novel finding that during the development experiment, presence of UV-A induced a decline in the rates of metamorphosis and settlement, which disappeared when the larvae were also exposed to UV-B (here defined as 295–320 nm). However, UVR had no distinguishable effect on the numbers of larvae that either survived, metamorphosed or settled by the end of the culture period. Therefore, it is concluded from this study that UV-A radiation may extend the planktonic duration of coral larvae, but not have an overall inhibitory effect on developmental outcomes.
AB - Coral reefs are vulnerable to ultraviolet radiation (UVR, 280–400 nm). Not only do the fluxes of UVR fluctuate daily, they are also increasing due to global ocean and atmospheric changes. The deleterious effects of UVR on scleractinian corals have been intensively studied, but much less is known about the response of corals in the early pre-settlement phase. In this study, we tested how UVR exposure affects survival and development of Seriatopora caliendrum larvae and examined the photophysiological changes induced in the symbiotic dinoflagellate Symbiodinium. Results showed that the contents of chl c and carotenoids normalized to the number of algae cells in the larvae decreased significantly when larvae were exposed to UVR compared to those protected from UVR, while the cell density of Symbiodinium was higher in UVR-exposed larvae. The effective photochemical efficiency of the symbiotic algae increased when cultured under PAR plus UV-A (here taken as 320–395 nm). We further present the novel finding that during the development experiment, presence of UV-A induced a decline in the rates of metamorphosis and settlement, which disappeared when the larvae were also exposed to UV-B (here defined as 295–320 nm). However, UVR had no distinguishable effect on the numbers of larvae that either survived, metamorphosed or settled by the end of the culture period. Therefore, it is concluded from this study that UV-A radiation may extend the planktonic duration of coral larvae, but not have an overall inhibitory effect on developmental outcomes.
KW - Coral larvae
KW - Settlement
KW - Symbiodinium
KW - Ultraviolet radiation
UR - http://www.scopus.com/inward/record.url?scp=85011928656&partnerID=8YFLogxK
U2 - 10.1016/j.jphotobiol.2017.01.007
DO - 10.1016/j.jphotobiol.2017.01.007
M3 - Article
AN - SCOPUS:85011928656
SN - 1011-1344
VL - 167
SP - 249
EP - 255
JO - Journal of Photochemistry and Photobiology B: Biology
JF - Journal of Photochemistry and Photobiology B: Biology
ER -